                Patent document 1: JP-2006-94477 A corresponding to US-2006/0040714        
Patent document 1 describes an in-vehicle handsfree apparatus which establishes a handsfree profile connection with a cellular phone, which is brought into a passenger compartment of a vehicle.
Some users carry several cellular phones together for private and business uses in recent years. Thus, the inventor assumes that an in-vehicle handsfree apparatus might be required to anticipate a case that multiple cellular phones are brought into a passenger compartment of the relevant vehicle. In other words, the inventor assumes that an in-vehicle handsfree apparatus might be required which has a function to establish a handsfree profile connection with each of the multiple cellular phones at the same time (referred to as a function for multi-profile connection) to thereby allow all the cellular phones to be in a handsfree standby state.
Further, even if an in-vehicle handsfree apparatus might be provided with such a function for multi-profile connection with multiple cellular phones as the inventor assumes, a situation might be assumed that while one of the cellular phones with which a handsfree profile connection is being simultaneously established is under a telephone call, another cellular phone may receive an incoming call. In such a situation, the inventor further assumes that if the cellular phone receiving the incoming call is compliant with an in-band ring tone, the in-vehicle handsfree apparatus necessarily receives a ring tone registered in the cellular phone receiving the incoming call and the received ring tone might be outputted along with a reception sound received from the cellular phone under the telephone call. This might cause a trouble in hearing the reception sound under the telephone call, resulting in worsening the usability.